Field of the Invention and Related Art Statement
This invention relates to a method for producing refreshable dry food, and more particularly to a method for vacuum-drying edible raw food such as beef, pork, mutton, and the like; fishes and shellfishes such as raw shrimp, adductor muscle, fish meat and the like; vegetables such as raw potato, raw onion and the like; and edible wild plants such as mushrooms and the like (hereinafter referred to as other food) at a low temperature of -10.degree. C. to 0.degree. C. in a semi-frozen state in such a manner that the thus dried meat or other food is refreshable substantially to the state of raw meat or other fresh food before drying.
A number of methods for preserving edible meat or other food by drying have been known: namely, non-restorable drying methods such as natural drying with solar energy and drying by blowing hot air over the food, and semi-restorable methods such as freeze-drying under vacuum conditions. However, none of the conventional methods for drying edible meat or other food produce dry meat or other food which can be restored to the quality equivalent to that of fresh meat or other food before drying. More particularly, with the conventional method of drying edible meat or other food, the inside texture of the fresh meat or other food is damaged in the process of freeze-drying, so that it is almost impossible to restore the thus dried meat or other dry food to conditions which closely resemble fresh meat or other fresh food. Thus, the use of dry meat or other dry food prepared by conventional methods has been limited to those which do not require restoration to fresh meat or other fresh food, such as those for canning.
Accordingly, there is a demand for a method for producing refreshable dry meat or other dry food which upon rehydration closely resembles fresh meat or other fresh food (to be referred to as "refreshable dry food" hereinafter) If any practicable methods for producing refreshable dry food are found, preservation of edible dry food for a long period of time would become possible and the need for refrigerators and cold storage facilities would be greatly curtailed. Besides, the refreshable dry food would weigh only about one third of fresh food, so that transportation and storage of food would be simplified to a considerable extent. Further, preservation of such refreshable dry food by vacuum packing or nitrogen packing with a highly airtight film would provide one of the most useful preserved food stuffs.